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United States Patent | 6,032,028 |
Dickey ,   et al. | February 29, 2000 |
An FM transmitter includes I and Q channels, each deriving a baseband sinusoidal wave having a frequency determined by speech and/or music broadcast information amplitude and nominally having the same maximum amplitude. Each wave drives a different balanced mixer, each responsive to orthogonally phased carrier waves. Outputs of the mixers are added to derive a frequency modulated output wave. The channels, mixers, and circuitry associated with them tend to introduce unwanted components in the output wave. Offset, peak amplitude, phase and relative delay of the added mixed outputs are such that the unwanted components are substantially eliminated from the output wave. The sinusoidal waves are derived by DACs responsive to signals derived by a digital processor having a memory storing amplitude vs. phase position values and slope vs. phase position values that are combined in response to samples of the broadcast information. The stored amplitudes and slopes control sinusoidal wave offset, peak amplitude and phase. The waves and delay times of the channels driving a power amplifier of the transmitter are calibrated on line according to certain embodiments.
Inventors: | Dickey; Daniel L. (Rowlett, TX); Hershberger; David L. (Nevada City, CA) |
Assignee: | Continentral Electronics Corporation (Dallas, TX) |
Appl. No.: | 794744 |
Filed: | February 3, 1997 |
Current U.S. Class: | 455/110; 332/117; 332/144; 455/103 |
Intern'l Class: | H04B 001/04 |
Field of Search: | 455/110-113,103,118,93,104,105,109,47,114 332/100-105,119,151,159,117,149,144,170 375/296,302,308,303,301 |
1941068 | Dec., 1933 | Armstrong. | |
3654450 | Apr., 1972 | Webb. | |
3689914 | Sep., 1972 | Butler. | |
3806806 | Apr., 1974 | Brolin. | |
3824498 | Jul., 1974 | McBride. | |
3825834 | Jul., 1974 | Stuart et al. | |
3913021 | Oct., 1975 | McCarthy et al. | |
3958191 | May., 1976 | Jones, Jr. | |
4003001 | Jan., 1977 | Jones, Jr. | |
4134072 | Jan., 1979 | Bolger. | |
4159527 | Jun., 1979 | Yahata et al. | |
4185247 | Jan., 1980 | Harrison, Jr. | |
4229821 | Oct., 1980 | de Jager et al. | |
4263565 | Apr., 1981 | Astle. | |
4304965 | Dec., 1981 | Blanton et al. | |
4315219 | Feb., 1982 | Rocheleau et al. | |
4328554 | May., 1982 | Mantione. | |
4331941 | May., 1982 | Kovalick et al. | |
4345500 | Aug., 1982 | Alonso et al. | |
4346477 | Aug., 1982 | Gordy. | |
4413236 | Nov., 1983 | Sochor. | |
4414632 | Nov., 1983 | Murrell. | |
4482974 | Nov., 1984 | Kovalick. | |
4482975 | Nov., 1984 | King et al. | |
4494073 | Jan., 1985 | Sorgi. | |
4516084 | May., 1985 | Crowley. | |
4603304 | Jul., 1986 | Burns et al. | |
4609881 | Sep., 1986 | Wells. | |
4646032 | Feb., 1987 | Wheatley, III et al. | |
4652832 | Mar., 1987 | Jasper. | |
4659999 | Apr., 1987 | Motoyama et al. | |
4682122 | Jul., 1987 | Remy et al. | |
4700390 | Oct., 1987 | Machida. | |
4707665 | Nov., 1987 | Nugent et al. | |
4794556 | Dec., 1988 | Rader. | |
4841256 | Jun., 1989 | Gastgeb. | |
4940984 | Jul., 1990 | Kleiber. | |
4947455 | Aug., 1990 | Swanson. | |
4984188 | Jan., 1991 | Kato. | |
4990867 | Feb., 1991 | Ogura et al. | |
5028887 | Jul., 1991 | Gilmore. | |
5093632 | Mar., 1992 | Hietala et al. | |
5122763 | Jun., 1992 | Saeki et al. | |
5146186 | Sep., 1992 | Vella. | |
5162763 | Nov., 1992 | Morris | 455/109. |
5202642 | Apr., 1993 | Dixon. | |
5220557 | Jun., 1993 | Kelley. | |
5231314 | Jul., 1993 | Andrews. | |
5254955 | Oct., 1993 | Saeki et al. | |
5291428 | Mar., 1994 | Twitchell et al. | |
5293407 | Mar., 1994 | Shibata | 332/103. |
5303412 | Apr., 1994 | Kushner. | |
5309474 | May., 1994 | Gilhousen et al. | |
5351016 | Sep., 1994 | Dent | 332/159. |
5353311 | Oct., 1994 | Hirata et al. | |
5394106 | Feb., 1995 | Black et al. | |
5404405 | Apr., 1995 | Collier et al. | |
5414390 | May., 1995 | Kovacs et al. | |
5422909 | Jun., 1995 | Love et al. | |
5430659 | Jul., 1995 | Miller. | |
5437281 | Aug., 1995 | Lin et al. | |
5467041 | Nov., 1995 | Baba et al. | |
5574994 | Nov., 1996 | Huang et al. | 375/296. |
5784412 | Jul., 1998 | Ichihara | 375/302. |